That is a type of keystone wall.
Is categorized as gravity wall.
Similar with those Reinforced Earth Wall that using gravity load to sustain the earth.

To retain the earth due to different in Reduce Level (RL).
Also can called as platform level in normal term.
Reduce Level is in Engineering or surveying terms.

Reduced level
Reduced Level in surveying refers to equating elevations of survey points with reference to a common assumed datum. It is a vertical distance between survey point and adopted datum plane. Thus it is considered as the base elevation which is used as reference to reckon heights or depths of other important places. Reduced here means equating and Level means Elevations. Datum may be real or imaginary location with a nominated elevation of straight zero.

Always remember that due to nature of ground terrain, it caused necessary to built retaining structure (in this case, gravity wall called keystone's wall) in order to separate the ground in two different REDUCE LEVEL where normal cannot be done by slope cutting methods.